Pipette assembly and package therefor



June 8, 1965 M. P. CORWIN PIPETTE ASSEMBLY AND PACKAGE THEREFOR Filed April '14, 1960 2 Sheets-Sheet l INVENTOR.

MLWIY P. 60PM June 8, 1965 M. P. CORWlN PIPETTE ASSEMBLY AND PACKAGE THEREFOR 2 Sheets-Sheet 2 Filefd April 14, 1960 INVENTOR.

A BY

K 11PM W United States Patent Office 3,187,888 Patented June 8, 1 965 3,187,888 PIPETTE ASSEMBLY AND PACKAGE THEREFOR Melvin P. Corwin, West Caldwell, N.J., assignor t Becton, Dickinson and Company, Rutherford, N.J., a corporation of New Jersey Filed Apr. 14, 1960, Ser. No. 22,213

4 Claims. (Cl. 206-56) This invention relates to a structurally and functionally improved pipette assembly and a package for use with parts of that assembly.

In its more specific aspects, the invention aims to provide an improved and/or alternative structure over that disclosed in the application for United States patent in the name of Horace W. Gerarde for Method ofProviding for Blood Count and Pipette and Assembly for Use Therein identified under Serial No. 721,139 and filed on March 13, 1958, which application has now matured into U.S. Patent No. 3,045,494.

By means of the present teachings a unit is provided which may be packaged and stored for long periods of time without loss of its contained diluent; the packaging procedure leading to this result being capable of ready achievement.

A further object is that of furnishing components of a pipette assembly which may readily be used by unskilled persons and which may be economically produced.

With these and other objects in mind, reference is had to the attached sheets of drawings illustrating one practical embodiment of the invention, and in which;

FIG. 1 is a perspective view of a package such as is preferably employed to contain a series ofreservoir elements each to form part of a pipette assembly;

FIG. 2 is a transverse sectional view taken along the line 22 in the direction of the arrows as indicated in FIG. 1;

FIG. 3 is a view similar to FIG. 1, showing a preferred type of packet or envelope for containing the capillary tubes and associated parts of the pipette assemblies;

FIG. 4 shows the units of a complete assembly in separated condition;

FIG. 5 is a transverse sectional view, in enlarged scale,

taken along the line 55 in the direction of the arrows as indicated in FIG. 4; and

FIG. 6 is a fragmentary partly sectional side elevation in enlarged scale of the adjacent end portions of the reservoir and capillary tube units of the assembly.

Referring primarily toFIGS. 1 and 2, a container or package for the reservoir units of the pipette assemblies has been illustrated. In accordance with the present teachings, this will include a pair of sheets 10 preferably formed of metal, as for example, aluminum foil, of a configuration such that their edge zones 11 may be subjected to a heat seal. At points short of the ends of sheets 10, zones 12 may be provided which can conveniently be heat sealed to furnish, beyond the same, tap portions will embrace the reservoir units with sufficient intimacy. to assure against theirbecoming displaced within the package or container. Therefore, the package may be handled with assurance by the user.

The reservoir unit, which will hereinafter be described in detail, forms one part of the pipette assembly. The

second part of the same includes a capillary tube and structures associated therewith, indicated in FIG. 3 in dash linesv by the numeral 18. These assemblies will preferably be included in a packet 19 formed of suitable paper. The number of capillary units should be identical with the number of reservoir units contained in one of the packages as shown in FIGS. 1 and 2. Therefore, an operator with one packet of capillary tube assemblies will know that by obtaining a package enclosing reservoirs, he will have available a certain number of "complete assemblies.

Now referring to the detailed structure of the capilla tube and associated parts, attention is directed to FIGS. 4, 5 and 6. In those views the numeral 20 indicates the tube proper, which is preferably formed of glass and has a bore of such minute cross-sectional area that with the end of the tube immersed in a drop of blood or other liquid and that tube inclined in an upward direction, the liquid will flow upwardly into the tube bore to completely fill the same. The internal capacity of the tube will be precisely known. The tube is supported, at'one end by a sleeve 21 and especially the reduced tip portion 22 thereof, to which it may be secured in any suitable manner. The cross-sectional area of the sleeve is much greater than that of tube 20. Therefore, with blood or other liquid rising within the bore of that tube, as aforedescribed, it is apparent that as the upper surface of the liquid reaches a position in line with the inner end of the tube, the capillary action will cease; the tubebeing then completely filled.

The sleeve is enclosed by or formed integrally with a layer 23 from which there extends a tab portion 24. The latter may be grasped in order to manipulate the capillary tube assembly. Also, this tab presents surfaces such that indicia may be applied thereto showing, for example, code numbers to identify the sample or solution and its origin, or else the name of a given physician, patient, etc. The ends of sleeve 21 extend beyond this tab portion, as indicated at 25 and 26, and are preferably tapered in an outward direction.

With a view to protecting the capillary tube 20, it is enclosed within a sheath. This preferably embraces a tubular body with a closed outer end, as indicated at 27. Also, it may be provided with rigidifying fins or ribs 28 on its outer face. The open end of the sheath defines a diameter substantially equal to the tapered end portion 26. Therefore, as illustrated in FIG. 4, the sheath may seat and be retained on this end portion to enclose tube 20.

The reservoir conveniently includes abody 29 which is tubular and provided with a base portion conveniently heat sealed, as at 30. In common with most if not all other parts of the assembly, this body is formed of polyethylene. Obviously, if desired, the reservoir may embrace numerous diiferent configurations defining a suitable vessel. In all events, the walls of the vessels should embody a certain degree of elasticity, or else some other obvious provision should be resorted to so that internal pressures within the reservoir may be varied. Additionally, it is definitely preferred, according to the present teachings, to have the outer wall 31 of the reservoir formed with an opening defined by a collar or flange 32. This opening is sealed by a plug comprising a body portion 33 of a diameter preferably slightly in excess of the normal bore diameter defined 'by collar 32. The outer end of the plug body terminates in an extended portion 34 which is preferably tapered. The zone of the plug between the-main body 33 and its opposite endis pref erably beveled, as at 34.

As will be understood, thecapillary tube assemblies, including the sheaths, are produced and assembled as shown in FIG. 4. Thereupon, they are conveniently packagedin the manner illustratedof diluent. If the units are intended for use in making counts "of red or whiterblood cells, the plugs sealing the reservoirs may conveniently be correspondingly colored,

so that an operator willnever be at 'a loss to determine the type of diluent present' in a. given reservoir. The bore capacity of the capillary tube 20 .and' the. volume of diluent are precisely related;

Parts of the assembly are formed of a material such as polyethylene. Having in mind the elasticity of materials of this type,'it is preferred that the? opening defined by collar 32 be of a diameter slightly less than of the tapered end portions 25 and 26. Accordingly, when an operator applies one of these end portions to the reservoir, by exerting slight pressure the different surfaces will conform to each other. in firm sealing. contact. The main body portion 33 of the plug is likewise preferably produced to have. a diameter slightly in excess of that of theopening definedby the collar 32. The beveled or tapered surface 34 of the" plug serves as a guide and will cam against the adjacent" surfaces of the reservoir opening to expand that opening to a small extent and thus facilitate the introduction of the. plug to a positionas illustrated in FIG. 4.

Under these circumstances, it is apparent that the plug is shaken. An unskilled operator atempting to withdraw' the plug ratherthan push the same inwardly will find it ditficult, if not impossible, to do so, in view of the tapered surfaces 34. Thus the possibility of errors is minimized.

Thereservoir being made of a material such as polyethylene, it follows that if the unit is stored or maintained under conditions not providing for a safeguard, the diluent will gradually pass through the walls of the reservoir; This will quickly diminish the volume of diluent to a point where reliable end results would no longer obtain. To overcome difficulties in this connection, immediately after the manufacture of the reservoir and the filling of the same with a proper volume of diluent, that reservoir Will be sealed by the plug and disposed within the container or package, as illustrated in FIGS. 1 and 2. So disposed, the inner surface of the foilor equivalent material defining each compartment will engage the surface of the contained reservoir to prevent movement of the same within the container. Prior to finally sealing the reservoir into the package, in, for example, the manner aforementioned, a suitable quantity of liquid, such as water, is introduced into the container. This liquid will be free to pass from one compartment to the'other, in that the indentations defining those compartments are not extended to a point where the latter are sealed from each other. Rather, passages alford communication between those compartments. With the package then sealed, it is found that the reservoir units will not be subject to having their contained diluent escape by passing through their walls. Rather, the water, or other liquid, provides a vapor barrier around each of the reservoir units, thereby equalizing the vapor pressure within and without such units. Accordingly, the package may be stored 'for long periods of time with'the volume of diluent remaining precisely the same in each reservoir.

dicated in FIG. 2. A reservoir unit may then be withdrawn, and any excess moisture on its exterior may be disposed of. A capillary tube assembly will be Withdrawn from the packet, as illustrated in FIG. 3. A drop of blood being present on the finger of the patient, the operator,

.sembly from. a position'adjacent the finger.

by grasping tab 234 or the ensleeving portion 23, may cause the assembly to assume. an upwardly inclined position. The free end of the capillary :tube will be immersed in the drop of blood, and that blood will instantly rise through the bore of the tube to completely fill the same.

? It will cease rising when its upper surface reaches the end of the capillary tube bore. a q

The operator will now' remove the capillary tube as- In an abundance of caution, that operator may place his index finger in line with the bore defined by the tapered end portion 25. This will assure against the escape of any blood or other liquid" from thebore of the capillary tube, even if the unit is subjected to violent movements. Manual pressure is brought to bear upon the projecting portion 34 ofthe plug to force it into the reservoir. The latter is compressed to a slight degree. Accordingly, by introducing the tapered end portion 26 of the sleeve into the opening defined by collar 32 to a point where thesurfa'ces seal against. each other, a release of pressure on the reservoir and removal of the index finger from the bore of part will result in an aspirating action which will draw all the blood'or other liquid within the bore of tube 20 into the interior of the reservoir;

Thereupon, the reservoir Walls may again be compressed, or else some other suitable procedure is resorted to, to cause the interior of the reservoir to be under pressure. In. either event, diluent will be forced up through the bore of tube 2ft and'even into the bore of sleeve 21, which under these circumstances is maintained in a substantiallyvertical position. Again, by resorting to an aspirating action, the liquid is drawn back into the res-. ervoir. This procedure may be repeated a number of times, if desired. it will obviously result in a scavenging of the bore surface of tube 24 so that the entire quantity of blood within that bore is transferred to the interior of the reservoir.

Conveniently, at this time tab 24 and its associated parts, after removal from the reservoir, may receive inclicia, if this be necessary. Thereupon, the capillary tube. assembly is again associated with the reservoir. However, in this latter instance the tapered end portion 25 is introduced into the opening defined by collar 32, sothat contrary to the illustration of FIG. 6, tube 29 extends outwardly from the reservoir. This tube may again be enclosed withinsheath 27. Under these circumstances, the unit may be handled or shipped, as desired.

Thus, among others, the several objects of the invention as specifically aforenoted are achieved. Obviously, numerous changes in construction and rearrangements of the parts may be resorted to without departing from the spirit of the invention as defined by the claims.

3 permeation which comprises a liquid reservoir in the form of a first container formed with an opening fitted with a closure and having a first quantity of liquid therein the volume of which being insuifi cient to fill said first container so that a vapor emanating from said first liquid fills the remainder of said first container, at least a portion of said first container being permeable to the vapor emanating from said first liquid, and a second container formed of a material substantially impervious to liquid.

and vapor enclosing said first' container and having a second quantity of liquid therein the volume. of which being insufiicient to fill said second container so that a' vapor emanating from said second liquid fills'the remainder of said second container to provide a vapor barrier around said first container for. substantially equalizing the vapor pressure within and withoutsaid first container so that during long storage the vapor from said first liquid 2. A package for a reservoir containing a quantity of liquid adapted to perform a biological testing function and serving to prevent loss of liquid therefrom by vapor permeation as set forth in claim 1 in which the closure can be forced through the opening into the first container to serve as a mixing bead.

3. A package for a plurality of reservoirs each containing a quantity of liquid adapted to perform a biological testing function and serving to prevent loss of liquid therefrom by vapor permeation which comprises a plurality of reservoirs in the form of a plurality of inner containers each formed with an opening fitted with a closure and having a first quantity of liquid therein the volume of which being insufficient to fill said inner container so that a vapor emanating from said first liquid fills the remainder of said inner container, at least a portion of said inner container being permeable to the vapor emanating from said first liquid, and an outer container formed of a material substantially impervious to liquid and vapor enclosing said inner containers and having a second quantity of liquid therein the volume of which being insufiicient to fill said outer container so that a vapor emanating from said second liquid fills the remainder of said outer container to provide a vapor barrier around said inner containers for substantially equalizing the vapor pressure within and without said inner containers so that during long storage the vapor from said first liquid will not permeate outwardly through said inner containers.

4. A package for a plurality of reservoirs each containing a quantity of liquid adapted to perform a biologi- 6 cal testing function and serving to prevent loss of liquid therefrom by vapor permeation as set forth in claim 3 in which the inner containers are arranged in spaced relationship and the outer container is formed to provide a plurality of compartments conforming generally in shape with the inner containers, said compartments having communication with each other so that the liquid and vapor freely communicate with all of the compartments to provide substantially uniform vapor pressure throughout the outer container.

References Cited by the Examiner UNITED STATES PATENTS 2,051,349 8/36 Goldberg 206-63.2 2,102,585 12/37 Schlumbohm 206.5 2,283,867 5/42 Flosdorf et a1 206-63.2 X 2,365,556 12/44 Karg 206-63.2 2,527,992 10/50 Greenberg 206-47 2,572,669 10/51 Sarge et a1.

2,626,647 l/53 Barton 150-.5 2,738,059 3/56 Elson 206-63.3 2,753,990 7/56 Chalfin et al. 206-47 2,879,818 3/59 Root 150-.5 2,895,606 7/59 Hoag 206-56 2,965,255 12/ 60 Gerarde 73-425.6 X

' FOREIGN PATENTS 804,824 11/58 Great Britain.

THERON E. CONDON, Primary Examiner. ROBERT EVANS, Examiner. 

1. A PACKAGE FOR A RESERVOIR CONTAINING A QUANTITY OF LIQUID ADAPTED TO PERFORM A BIOLOGICAL TESTING FUNCTION AND SERVING THE PREVENT LOSS OF LIQUID THEREFROM BY VAPOR PERMEATION WHICH COMPRISES A LIQUID RESERVOIR IN THE FORM OF A FIRST CONTAINER FORMED WITH AN OPENING FITTED WITH A CLOSURE AND HAVING A FIRST QUANTITY OF LIQUID THEREIN THE VOLUME OF WHICH BEING INSUFFICIENT TO FILL SAID FIRST CONTAINER SO THAT A VAPOR EMANATING FROM SAID FIRST LIQUID FILLS THE REMAINDER OF SAID FIRST CONTAINER, AT LEAST A PORTION OF SAID FIRST CONTAINER BEING PERMEABLE TO THE VAPOR EMANATING FROM SAID FIRST LIQUID, AND A SECOND CONTAINER FORMED OF A MATERIAL SUBSTANTIALLY IMPERVIOUS TO LIQUID AND VAPOR ENCLOSING SAID FIRST CONTAINER AND HAVING A SECOND QUANTITY OF LIQUID THEREIN THE VOLUME OF WHICH BEING INSUFFICIENT TO FILL SAID SECOND CONTAINER SO THAT A VAPOR EMANATING FROM SAID SECOND LIQUID FILLS THE REMAINDER OF SAID SECOND CONTAINER TO PROVIDE A VAPOR BARRIER AROUND SAID FIRST CONTAINER FOR SUBSTANTIALLY EQUALIZING THE VAPOR PRESSURE WITHIN AND WITHOUT SAID FIRST CONTAINER SO THAT DURING LONG STORAGE THE VAPOR FROM SAID FIRST LIQUID WILL NOT PERMEATE OUTWARDLY THROUGH SAID FIRST CONTAINER. 